arm: add iomem.h and phys_to_virt.h

Fixes build for arm.

This patch is equivalent to upstream commit 1574ff1aae4f3 (arm: include
phys_to_virt.h and iomem.h in distribution) when applied to the tarball.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>

---
diff -Nuar kexec-tools-2.0.13-orig/kexec/arch/arm/iomem.h kexec-tools-2.0.13/kexec/arch/arm/iomem.h
--- kexec-tools-2.0.13-orig/kexec/arch/arm/iomem.h	1970-01-01 02:00:00.000000000 +0200
+++ kexec-tools-2.0.13/kexec/arch/arm/iomem.h	2016-10-21 09:45:27.495689269 +0300
@@ -0,0 +1,9 @@
+#ifndef IOMEM_H
+#define IOMEM_H
+
+#define SYSTEM_RAM		"System RAM\n"
+#define SYSTEM_RAM_BOOT		"System RAM (boot alias)\n"
+#define CRASH_KERNEL		"Crash kernel\n"
+#define CRASH_KERNEL_BOOT	"Crash kernel (boot alias)\n"
+
+#endif
diff -Nuar kexec-tools-2.0.13-orig/kexec/arch/arm/phys_to_virt.h kexec-tools-2.0.13/kexec/arch/arm/phys_to_virt.h
--- kexec-tools-2.0.13-orig/kexec/arch/arm/phys_to_virt.h	1970-01-01 02:00:00.000000000 +0200
+++ kexec-tools-2.0.13/kexec/arch/arm/phys_to_virt.h	2016-10-21 09:45:27.495689269 +0300
@@ -0,0 +1,8 @@
+#ifndef PHYS_TO_VIRT_H
+#define PHYS_TO_VIRT_H
+
+#include <stdint.h>
+
+extern uint64_t phys_offset;
+
+#endif